Powertrain, generic · Transmission

P0751 Shift Solenoid A Performance/Stuck Off

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

A shift solenoid is an electrically switched valve in the valve body; together the solenoid states select the gear, and the module checks the result by gear ratio, slip or a pressure switch – the pattern of wrong gears shows which solenoid hangs off or on. P0751 means solenoid A is commanded on but valve, clutch or gear do not follow. GM's 6T70 flags a ratio of 1.34–1.48 with slip of 400 rpm for 0.3 s eight times and locks out first gear; GM 4-speeds recognise the pattern 2-2-3-3; both after two trips. Allison checks its pressure switch for 5 s after one trip. Ford's 'functionally failed off' covers the whole clutch circuit, and its 10R80 and 8F35 bulletins show purely mechanical causes such as a leaking clutch cylinder.

Likely causes

Shift spool in the valve body sticking (dirt, debris)
Internal leak or clutch fault in the circuit
Solenoid mechanically sluggish or screen clogged
Fluid level or quality wrong

Symptoms

  • Gears missing or skipped
  • Pulling away in the wrong gear, weak acceleration
  • Limp mode or gear lock-out
  • Check engine light

Repair estimate

DifficultyHardWorkshop job
Parts and labour€200–3,500
Time2–12 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift solenoidtransmission valve bodytransmission wiringtransmission control module

Related codes

P0752P0750P0753P0731P0732P0747

References: saabwisonline.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.